Archive for the ‘General’ Category

Comment editing is now possible

Friday, May 28th, 2021

It took a while, but now Launchpad finally allows users to edit their comments on questions, bug reports and merge proposal pages.

The first request for this feature dates back from 2007. Since then, Launchpad increased a lot in terms of new features, and the other priorities took precedence over that request, but the request was still more than valid. More recently, we managed to bump the priority of this feature, and now we have it: users are now allowed to edit their comments on Launchpad answers, bugs and merge proposals!

This has been available in the API for a few days already, but today we finally released the fresh new pencil icon in the top-right corner of your messages. Once you click it, the message is turned into a small form that allows you to edit your message content.

For messages that were edited before, it is possible to see old versions of that edited message by clicking the “last edit …” link, also at the top of the message.

In case you introduce sensitive information by mistake in your comment and need to remove it from the message history after editing it, you can always use the API to do so. We plan to add a remove button to the message’s revision history UI soon, to make this work easier.

The Launchpad team is proud of this new feature, and we hope that it will be useful for everyone! Let us know if you have any feedback!

Login regression for users with non-ASCII names

Thursday, August 20th, 2020

On 2020-08-13, we deployed an update that caused users whose full names contain non-ASCII characters (which is of course very common) to be unable to log into Launchpad. We heard about this serious regression from users on 2020-08-17, and rolled out a fix on 2020-08-18. We’re sorry about this; it doesn’t meet the standards of both inclusion and quality that we set for ourselves. This post aims to explain what happened, technical details of why it happened, and the steps we’ve taken to avoid it happening again.

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Launchpad news, March 2019 – July 2019

Tuesday, August 6th, 2019

Here’s a brief changelog of what we’ve been up to since our last general update.

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Launchpad news, February 2019

Thursday, March 7th, 2019

Here’s a brief changelog for this month.

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Launchpad news, July 2018 – January 2019

Thursday, February 21st, 2019

Here’s a brief changelog of what we’ve been up to since our last general update.

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Launchpad news, June 2018

Friday, July 6th, 2018

Here’s a brief changelog for this month.

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Launchpad news, May 2018

Saturday, June 2nd, 2018

Here’s a brief changelog for this month.

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Launchpad news, June 2017 – April 2018

Tuesday, May 1st, 2018

Once again it’s been a while since we posted a general update, so here’s a changelog-style summary of what we’ve been up to.  As usual, this changelog preserves a reasonable amount of technical detail, but I’ve omitted changes that were purely internal refactoring with no externally-visible effects.

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Launchpad security advisory: cross-site-scripting in site search

Wednesday, April 11th, 2018

Summary

Mohamed Alaa reported that Launchpad’s Bing site search implementation had a cross-site-scripting vulnerability.  This was introduced on 2018-03-29, and fixed on 2018-04-10.  We have not found any evidence of this bug being actively exploited by attackers; the rest of this post is an explanation of the problem for the sake of transparency.

Details

Some time ago, Google announced that they would be discontinuing their Google Site Search product on 2018-04-01.  Since this served as part of the backend for Launchpad’s site search feature (“Search Launchpad” on the front page), we began to look around for a replacement.  We eventually settled on Bing Custom Search, implemented appropriate support in Launchpad, and switched over to it on 2018-03-29.

Unfortunately, we missed one detail.  Google Site Search’s XML API returns excerpts of search results as pre-escaped HTML, using <b> tags to indicate where search terms match.  This makes complete sense given its embedding in XML; it’s hard to see how that API could do otherwise.  The Launchpad integration code accordingly uses TAL code along these lines, using the structure keyword to explicitly indicate that the excerpts in question do not require HTML-escaping (like most good web frameworks, TAL’s default is to escape all variable content, so successful XSS attacks on Launchpad have historically been rare):

<div class="summary" tal:content="structure page/summary" />

However, Bing Custom Search’s JSON API returns excerpts of search results without any HTML escaping.  Again, in the context of the API in question, this makes complete sense as a default behaviour (though a textFormat=HTML switch is available to change this); but, in the absence of appropriate handling, this meant that those excerpts were passed through to the TAL code above without escaping.  As a result, if you could craft search terms that match a portion of an existing page on Launchpad that shows scripting tags (such as a bug about an XSS vulnerability in another piece of software hosted on Launchpad), and convince other people to follow a suitable search link, then you could cause that code to be executed in other users’ browsers.

The fix was, of course, to simply escape the data returned by Bing Custom Search.  Thanks to Mohamed Alaa for their disclosure.

Launchpad news, May 2017

Wednesday, May 31st, 2017

Here’s a brief changelog for this month.

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